spinule and some small denticles.

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1 Anoplodactylus ophiurophilus n. sp. a sea spider associated with brittle stars in the Seychelles by Jan H. Stock Institute of Taxonomic Zoology (Zoologisch Museum) University of Amsterdam The Netherlands Abstract Description A new species of Pycnogonida Anoplodactylus ophiurophilus is described. It is associated with three species of the genus Ophiocoma in the Seychelles (Indian Ocean) and constitutes the first recorded case of a sea spider found on Ophiuroidea. In comparison with the 83 species actually recognized in Anoplodactylus the new species shows hardly any morphological adaptations due to this remarkable association. Résumé Une nouvelle de espèce Pycnogonides Anoplodactylus ophiurophilus est décrite. Elle est associé à trois espèces du genre Male: Trunk with indistinct segmentation lines on the dorsal surface more distinct ones on the ventral side. Neck short expanded in front of the first lateral. Lateral in touching their basal part separated distally; distodorsally armed with two or three small spines. Ocular tubercle low directed anteriad rounded eyes not visible at Ophiocoma aux Seychelles (Océan Indien) le premier cas least in preserved material; lateral sense organs connu d un Pycnogonide rencontré sur des Ophiures. En comparaison avec les 83 espèces reconnues dans le genre Anoplodactylus l espèce nouvelle ne montre guère d adaptations morphologiques relatives à cette INTRODUCTION association remarquable. To Dr. N. A. Sloan Queen Mary College University of London I?m indebted for entrusting me with a Anoplodactylus ophiurophilus n. sp. (Figs. 19) number of small pycnogonids Material examined: One ovigerous $ (holotype) 1 9 (allotype); 10 ovigerous ss (paratypes). Aldabra atoll Seychelles (09 24'S 46 20'E) in very shallow waters (eu and sublittorai) Feb Associated with the ophiuroid iophiocoma doederleinide Loriol 1899 (Zoologisch Museum Amsterdam coll. no. Pa ). found in remarkable abundance clinging to the ventral (oral) side of the arms of ophiuroids of the genus Ophiocoma in the Seychelles (Indian Ocean). Ophiocoma doederleini De Loriol 1899 had the highest incidence of pycnogonid associates; lower infestation rates were found on O. erinaceus Miiller & Troschel 1842 and O. pica Miiller & Troschel 1842 (see Sloan in preparation for detailed data on infestation rates and the nature of the association). The pycnogonid proved to be a new species of the large genus Anoplodactylus which will be described in the sequel. present as small on the lateral surface of the ocular tubercle in subterminal position. Abdomen about as long as the fourth lateral directed upward at an angle of some 35. The entire trunk including the ocular tubercle the lateral and the abdomen covered with a short pubescence. Proboscis straight almost cylindrical slightly wider subterminally (type B"'to D'" according to the classification of Fry & Hedgpeth 1969: 20 21). Chelifore scape pubescent chela almost as long scape. Palm with some spinules; immovable as finger shorter than the palm strongly curved armed with two small denticles; movable finger longer than the palm less curved armed with a spinule and some small denticles. very No trace of palps. Oviger 6segmented; relative lengths of the segments and 6% (total: 100%). Reversed spines are numerous on segment 5. Segment 6 triangular small. Eggs on small oviger (diameter 4453 and very numerous. Like the trunk the legs are covered with short setules. No genital Sexual spur. apertures found with certainty only on coxa 2 of 4. Femur leg with a single short cement gland duct in just

2 BIJDRAGEN TOT DE DIERKUNDE 48 (2) Figs. 19. Anoplodactylus ophiurophilus n. sp. paratypes: 1 trunk dorsal (scale A); 2 trunk dorsal (A); anterior 3 part of the body 9 ventral (A); 4 chelifore (B); 5 oviger (B); 6 third leg (A); 7 cement gland aperture (C); 8 segments of third leg (B); 9 basal segments of third leg (A). distal front of the middle of the segment on its dorsal surface. Femur the longest tibia 2 the shortest of Female: Trunk more slender; lateral slightly more widely separated; segmentation lines the longer leg segments. Tarsus of normal shape more distinct also on the dorsal surface of the (not wedgeshaped). Propodus with a very strong heel armed with two heavy spines; sole with two trunk. Proboscis as in male thus without ventral outgrowths. No palps no ovigers. Sexual apertures basal and two distal spines but without the usual on coxa 2 of all legs; no genital spur. Femur row of regular spinules and without a lamina. Claw strongly swollen. Otherwise the morphology is strong curved without any trace of auxiliary claws. similar to that of the male.

3 coxa 158 J. H. STOCK ANOPLODACTYLUS OPHIUROPHILUS N. SP. Measurements of two paratypes in mm 30. inermis LosinaLosinsky 1961 $ 9 Length cephalic somite of ocular (from tip tubercle) second trunk somite Length Length third trunk somite fourth Length trunk somite (to tip of fourth lateral ) Length abdomen Width across second lateral Length proboscis (ventral) Greatest width proboscis Third leg coxa coxa 3 femur tibia tibia tarsus propodus claw Distinction from other species 31. insigniformis Stock insignis (Hoek 1881) (ex Phoxichilidium) 33. iuleus Stock jonesi Child jungersi Fage laminifer Arnaud lentus Wilson longiceps Stock 1951 (pro A. longicollis Williams 1941 preoccupied) 39. longiformis Child mamillosus Stock marcusi (de MelloLeitao 1949) (ex Halosoma) 42. maritimus Hodgson massiliensis Bouvier massiliformis Stock micros Bourdillon minusculus Clark minutissimus Stock n. sp. Stock in press (pro A. robustus Stock non Dohrn 1881) 49. multiclavus Child neglectus Hoek nodosus Hilton 1939 I recognize at least provisionally 83 valid species 52. oculatus Carpenter 1905 in the genus Anoplodactylus which are listed in 53. oculospinus Hilton pacificus Hilton 1942 alphabetical sequence below. Also enumerated are the species requirenda as well as a number of taxa that are at present considered synonyms homonyms or alternative spellings. 1. aculeatus Mdbius anarthrus Loman angulatus (Dohrn 1881) (ex Phoxichilidium) 4. aragaoi Sawaya arcuatus Child arescus Marcus arnaudae Stock australis (Hodgson 1914) (ex Phoxichilidium) bahamensis Child batangensis (Heifer 1938) (ex Pycnosoma) 11. brasiliensis Hedgpeth 1948 (pro A. pygmaeus Marcus 1940 non Hodge 1864) 55. pectinus Hedgpeth pelagicus Flynn petiolatus (Kroyer 1844) (ex Phoxichilidium) 58. pharus Stock polignaci Bouvier portus Caiman pulcher Carpenter 1907 pycnosoma (Heifer 1938) (ex Peritrachia) 62. pygmaeus (Hodge 1864) (ex Pallene) quadratispinosus Hedgpeth robustus (Dohrn 1881) (ex Phoxichilidium) 66. simplex Clark simulator Stock spinosus (LosinaLosinsky 1961) (ex Phoxichilidium) 69. squalidus Clark stictus Sawaya stocki Bacescu tarsalis Stock brericollis Loman californicus Hall capensis (Flynn 1928) (ex Phoxichilidium) 15. compactus Hilton coxalis Stock toros Child & Hedgpeth trispinosus Stock tubiferus (Haswell 1884) (ex 76. turbidus Stock typhlops Sars 1888 Phoxichilidium) 17. cribellatus Caiman n. sp. Stock in press (pro A. virescens Arnaud 1974 non Hodge 1864) 19. derjugini LosinaLosinsky digitatus (Bohm 1879) (ex Phoxichilidium) 78. unilobus Stock unospinus Hilton 1942 versluysi Loman virescens (Hodge 1864) (ex Phoxichilidium) 82. viridintestinalis (Cole 1904) (ex Halosoma) 21. erectus Cole xenus nom. Nov. (pro A. haswelli Stock 1954 non 22. eroticus Stock evansi Clark 1963 Flynn see 1918 Clark 1963: 49) 24. evelinae Marcus gestiens (Ortmann 1890) (ex Phoxichilidium) Species inquirenda homonyms synonyms alternative names: 26. glandulifer Stock 1954 angulirostris (Dohrn 1881: ) nom. alt. pro A. 27. guyanensis Child haswelli (Flynn 1918) (ex Halosoma) 29. hokkaidoensis (Utinomi 1954) (ex Phoxichilidium) angulatus (Dohrn 1881). antillianus Stock 1975 jun. syn. of A. jonesi Child carvalhoi Marcus 1940 jun. syn. of A. portus Caiman 1927.

= 1979 BIJDRAGEN TOT DE DIERKUNDE 48 (2) 159 exiguus (Dohrn 1881) (ex Phoxichilidium) jun. syn. of A. pygmaeus (Hodge 1864). hedgpethi Bacescu 1959 (as A. petiolatus hedgpethi) species inquirenda aff.

4 = 1979 BIJDRAGEN TOT DE DIERKUNDE 48 (2) 159 exiguus (Dohrn 1881) (ex Phoxichilidium) jun. syn. of A. pygmaeus (Hodge 1864). hedgpethi Bacescu 1959 (as A. petiolatus hedgpethi) species inquirenda aff. guyanensis Child insignis bermudensis Cole 1904 (identical with insignis s. str.). intermedius of Hilton 1942 jun. syn. A. batangensis (Heifer 1938). investigatoris Caiman 1923 jun. syn. of A. digitatus (Bohm 1879). lappa (Bohm 1879) (ex Pallene) species inquirenda. longicollis (Dohrn 1881) jun. syn. of A. petiolatus (Krayer 1844). longicollis Williams 1941 homonym of longicollis (Dohrn 1881); now: A. longiceps Stock longirostris (Dohrn 1881: 34) nom. alt. pro longicollis (Dohrn 1881). maritimus sensu Hedgpeth 1948 (non Hodgson 1914) A. iuleus Stock mutilatus (Frey & Leuckart 1847) (ex Phoxichilidium) species inquirenda. parvus Giltay 1934 jun. syn. of A. maritimus Hodgson parvus (Hilton 1939) (ex Phoxichilidium) homonym of parvus Giltay 1934; now: A. hokkaidoensis (Utinomi 1954). plumulariae (Von Lendenfeld 1883) (ex Phoxichilidium) species inquirenda. projectus Hilton 1942 jun. syn. of A. portus Caiman 1927 robustus Hilton 1939 homonym of A. robustus (Dohrn 1881); jun. syn. of A. portus Caiman robustus Zilberberg 1963 (non Dohrn 1881); cf. A. marcusi (de MelloLeitao 1949). saxatilis Caiman 1923 jun. syn. of A. digitatus (Bohm 1879). spinosus Mobius transferred 1902; to Parapallene. stylirostris Hedgpeth 1948 jun. syn. of A. batangensis (Heifer 1938). stylops Loman 1908 jun. syn. of A. pulcher Carpenter tenuirostris Lebour 1948 jun. syn. of A. batangensis (Heifer 1938). intestinalis (here again the condition of the cement is gland aperture unknown in the same 15 species as in the preceding paragraph). The 37 species listed below differ from A. ophiurophilus n. sp. in possessing a distinct propodal lamina (9 <5): aragaoi arcuatus arescus arnaudae bahamensis cribellatus digitatus erectus gestiens glandulifer brasiliensis compactus guyanensis iuleus jonesi jungersi laminifer longiformis mamillosus maritimus micros minusculus minutissimus multiclavus nodosus oculospinus pacificus petiolatus pharus pygmaeus stictus stocki tarsalis toros trispinosus turbidus viridintestinalis (the condition of the propodal armature is unknown for one species). One species batangensis has a styliform proboscis (? S) of a shape quite unlike that of the new present species (the shape of the proboscis is known for all 83 species listed above). The following 11 species are known to possess ventral outgrowths on the 2 proboscis whereas the presently described species is devoid of such outgrowths: arnaudae brevicollis digitatus evansi insignis jungersi polignaci portus stictus unilobus versluysi (the condition of the? proboscis is unknown for 19 species e.g. because the female sex is unknown). Most species of the viz. genus 75 possess rudimentary auxiliary claws. Only eight species are A. devoid of auxiliaries a condition shared by ophiurophilus n. sp. These eight species are: aculeatus anarthrus arescus batangensis pectinus pygmaeus stictus and tarsalis. Of the 83 species enumerated above the following 14 differ from A. ophiurophilus n. sp. in The above comparisons show that only two having the femoral cement glands ($ ) discharging species of Anoplodactylus share the six character through more than one aperture on each leg: angulatus australis cribellatus. "n. no. sp. 18" glandulifer hokkaidoensis longiceps longiformis states used in the preceding lines with A. ophiurophilus n. viz. A. sp. aculeatus and A. anarthrus. The former of these two aculeatus does not resemble in the least the new species multiclavus oculatus pycnosoma robustus virescens and xenus (the condition of the cement gland since it possesses long spurs on the coxae femur and first is unknown for 15 species e.g. of those species is unknown). because the male tibia has chelae with closing (as opposed to gaping) fingers and carries a regular row of Another 9 species have a single cribriform or spinules on the propodal sole (in fact A. aculeatus porelike cement gland aperture (S) at any rate is very close to if not identical with A. insignis). not a ductlike one as in the new species described The second of the two species anarthrus is more above: compactus evelinae insignis lentus massi similar to A. ophiurophilus n. sp. but possesses a liensis "n. sp. no. 48" pectinus polignaci virid row of six regular spinules of a size on the pro II

5 ANOPLODACTYLUS 160 J. H. STOCK OPHIUROPHILUS N. SP. podal sole and has touching (as opposed to separated) lateral. It is clear therefore that the material from the Seychelles represents an undescribed species which genus with only few representatives in temperate A. cool A. (e.g. petiolatus) (e.g. laminifer) or A. polar (e.g. australis) waters. Several representatives of the have been genus found however I propose to call A. ophiurophilus in virtue of its in cooler deep waters (e.g. A. amaudae A. ocu unique association with ophiurans of the genus latus) There is no doubt that the genus reaches Ophiocoma. It is remarkable though that the pycnogonid has developed so few morphological its greatest proliferation in the tropics of both the IndoPacific and the Caribbean. adaptations to its peculiar modeof life. As point of fact the new species could almost be considered a generalized Anoplodactylus without any striking characters. The only however slight adaptation REFERENCES (A complete bibliography of the Pycnogonida can be found in Fry & Stock 1978) might be found in the morphology of the propodus which is strongly curved lacking the usual row of sole spines and forming with the opposing FRY W. G. & J. W. HEDGPETH The fauna of the Sea 7. Pycnogonida 1. Colossendeidae Pycnogonidae Ross Endeidae Ammotheidae. Mem. N.Z. oceanogr. claw a strongly prehensile device. Inst. 49 (= Bull. N.Z. Dep. scient. ind. Res. 198): Up to now not a was known single pycnogonid to be associated with ophiuroids although other echinoderm groups are reported as possible food source (Holothuroidea Echinoidea; refs. in Stock Members 1978). of the genus Anoplodactylus have been recorded mainly from different groups of hydroids (refs. in King 1973 tables III & IV) and medusae but the closely related genus Pycnosoma was recorded from the echinoderm Strongylocentrotus a sea urchin by LosinaLosinsky 1933 Anoplodactylus is predominantly a warmwater FRY W. G. & J. H. STOCK A pycnogonid bibliography. Zool. J. Linn. Soc. Lond. 63 (1/2): KING P. E Pycnogonids: 1144 (Hutchinson London). LOSINALOSINSKY L. K Die Pantopoden der ostlichen Meere der U.S.S.R. Issled. Morei S.S.S.R. 17: SLOAN N. A. in preparation. An interesting pycnogonidophiuroid association. Mar. Biol. STOCK J. H Experiments food on preferences and chemical sense in Pycnogonida. Zool. J. Linn. Soc. Lond. 63 (1/2): in press. Pycnogonida from the mediolittoral and infralittoral zones in the tropical western Atlantic. Stud. Fauna Curacao. Received: 27 September 1978

Author(s) Nakamura, Koichiro; Chullasorn, Sup.

Title Eurycyde flagella, a New Pycnogonid Island, Thailand Author(s) Nakamura, Koichiro; Chullasorn, Sup Citation PUBLICATIONS OF THE SETO MARINE BIO LABORATORY (2000), 39(1): 1-7 Issue Date 2000-12-25